SEDGE FAMILY. j 



22. Cyperus Engelmanni Steud. Engelmann's Cypenis. (Fig. 564.) 



Cyperus Engelmanni Steud. Syn. PI. Cyp. 47. 1855. ' 



Annual, culms slender, 6 / -2' / 4 tall. Leaves 

 elongated, 2 // -3 // wide, flaccid, roughish on the 

 margins, those of the involucre 4-6, the longer 

 exceeding the umbel; umbel often compound, the 

 raylets very short; spikelets often densely crowded, 

 very narrowly linear, subterete, 6 // -i2 // long, 

 5~i5-flowered ; rachis narrowly winged ; scales 

 greenish-brown, oblong, obtuse, thin, faintly 3-5- 

 nerved on the back, distant, the successive ones 

 on each side of the spikelet separated by a space 

 of about one-half their length; stamens 3; style 

 3-cleft; achene linear-oblong, 3-angled, two-thirds 

 as long as the scale. 



In wet soil, Massachusetts to southern Ontario and 

 Wisconsin, south to New Jersey and Missouri. Aug.- 



Cyperus strigosus L. Straw-colored Cyperus. (Fig. 565.) 



Cyperus strigosus L. Sp. PI. 47. 



Perennial by basal tuber-like conn*, culm 

 rather stout, i-3 tall. Leave* omewhat 

 rough-margined, 2"-3" wide, the longer 

 ones of the involucre much exceeding the 

 umbel; umbel several-rayed, compound or 

 nearly simple, some of the primary ray* 

 often 4'-6' long, their sheath* terminating in 

 2 bristles; involucels setaceous; head* ob- 

 long or ovoid; spikelets flat, linear. 4 // -9 // 

 long, i" wide or less, 7-i5-flowered, ep- 

 rating from the axis at maturity; Kale* 

 straw-colored, oblong-lanceolate, subacote. 

 strongly several-nerved, appre**ed or at 

 length somewhat spreading; stamen* 3; 

 style 3-cleft; acbene linear-oblong, 3 angled, 

 acute, about one-third as long a* the *cale, 



In moist meadows, swamp* or aloof 

 Maine and ( Uitario to Minnesota, oath to Flor- 

 ida and Texas. Aug.-Oct 



Among the numerous form* of 

 the following may l defined a* r ~ 



Cyperus strigosus capitatus Boeckl. Linnaca, 36: 347- 1860-70. 



Umbel simple or nearly so; spikelets 4"-/' long, densely capitate in snbKloboat head*. 



of the type. 



Cyperus strigosus compositus Britton, Bull. Torr. Club, 13 



Umbel very compound; heads cylindric; spikelets 3" -6" long, 4-6-flowered. 

 York and Pennsylvania to Alabama. 



Cyperus strigosus robiistior Kunth, Knum. a: 81 

 Umbel compound; spikelets 8"-i2" long, io-25-flowered. Range of the type. 





